In the spring of 1947, six Scandinavian explorers noticed a strange phenomenon while crossing the Pacific Ocean. Somehow, small squid known to live deep beneath the waves kept appearing on the roof of their boat. The crew was mystified— until they saw the squids soaring above the sea for roughly 50 meters.
1947年的春天,六位 斯堪地納維亞探險家橫渡太平洋時 注意到一個奇異的現象。 不知為何,原先生活在 海面之下的小魷魚 一直出現在他們的船頂。 成員們對此感到困惑—— 直到看見一群魷魚 在海面上飛行約50公尺。
On land, people could barely believe the explorers. It seemed impossible that sea creatures without wings or bones could fly at all, let alone travel half the length of a football field. But over the next several decades, more reports began to surface. Sailors described airborne squid keeping pace with motor boats. Researchers reported captive squid escaping their tanks overnight. And as cameras became widespread, seafarers finally began capturing proof of these high-flying cephalopods. But how and why do these marine creatures take to the sky?
陸地上的人們難以相信這些探險家。 沒有翅膀跟骨頭的海洋生物 根本不可能飛起來, 更不用說能飛過足球場一半的長度了。 然而接下來幾十年內 出現了更多類似的回報。 水手描述有飛在空中的魷魚 和船艇並肩同行。 研究人員回報魷魚 在一夜之間逃離水缸。 隨著相機的普及, 航海者們終於能捕捉到 這些頭足類生物在空中飛的證據。 這些海洋生物是怎麼飛上天的? 又有什麼原因讓牠們得飛行?
While only a few squid species have been recorded taking flight, most squid are alike in the way they traverse the ocean. The outside of a squid’s body is a massive tube of muscle called the mantle. Water enters that tube through small openings around the squid’s head. Then, muscles clamp these openings shut, and the squid forcefully pumps the water through the base of their body. In practice, this makes the mantle a miniature jetpack, propelling squid through the water at 10 kilometers per hour. This process is also how squid breathe. Squid gills rest inside the mantle, and siphon oxygen from the water being pushed past them. With gills full of air and a mantle full of water, squid can outpace predators and pursue their prey. Or, in the case of some species, they can smash through the ocean’s surface, and attempt an epic flight.
然而紀錄中只有少數魷魚品種會飛行, 大部分魷魚則是以相同的方式 穿梭於海洋之中。 魷魚身體外部由一根被稱為外套膜的 大型肌肉管組成。 水由魷魚頭部周圍的小開口 進入該肌肉管中。 然後,藉由肌肉收縮讓那些開口閉上, 接著魷魚用力將水從身體底部擠出。 這個動作讓魷魚的外套膜 變成一個微型的噴射背包, 以每小時10公里的速度推動魷魚。 這個過程也是魷魚呼吸的方式。 魷魚的腮位於其外套膜內, 腮從經過的水中吸取收氧氣。 有了吸滿空氣的腮和充滿水的外套膜, 魷魚才能逃離掠食著,並追捕其獵物。 又或者,就某些魷魚品種來說, 讓牠們能衝破海洋表面, 並嘗試進行一場史詩般的飛行。
Without the resistance of water, a squid’s acceleration is the same as a car going from zero to 100 kilometers per hour in just over a second. At speeds of 40 kilometers per hour, squid quickly generate aerodynamic lift. But to stay in the air they’ll need something like wings. Fortunately, our soaring cephalopod has a plan. Squid tentacles are "muscular hydrostats," meaning the tissue can be held firm by muscle tension. Splaying its tentacles in a rigid formation, the squid transforms them into flexible wing-like structures that stabilise its flight. At the opposite end of its body, two fins typically used for gentle swimming find new purpose as a second set of wings. And by folding these fins down, a squid can streamline itself and dip back into the ocean.
少了水的阻力, 魷魚飛行速度就像一台車一樣, 從每小時0公里加速到100公里 只要一秒多。 魷魚以每小時40公里的速度 迅速製造氣動升力。 若想繼續留在空中,牠們就 需要某種類似翅膀的構造。 幸運的是,我們的飛行魷魚早有打算。 魷魚的觸手為「肌肉型液壓結構」, 組織能藉肌肉收縮 保持固定型態。 張開觸手擺成固定的結構, 魷魚將自己轉換成具彈性的類翼構造, 在飛行中保持穩定。 身體末端原本用於平衡游行的兩片鰭 找到了作為第二對翅膀的新用途。 透過將鰭往下摺的方式, 魷魚能使身體轉為流線型, 並潛入水面重返海洋。
There have been too few observations to establish what a squid’s typical flight trajectory looks like. Based on their flying speed, a 10 centimeter squid could hypothetically launch itself six meters above the water. But from what scientists have seen, flying squid tend to glide low, keeping close to the surface. This trajectory allows squid to cover the most horizontal distance possible over a typical several second flight. It also makes it easy to dive back into the water for more fuel— or to make a quick escape from predatory birds.
目前缺乏足夠的觀測資料, 來建立出魷魚的典型飛行軌跡。 根據魷魚的飛行速度, 一隻身長十公分的魷魚, 理論上能躍離海面六公尺。 但就科學家的觀察來看, 飛行魷魚傾向低空緊貼海面滑行, 這樣的軌跡讓魷魚在 幾秒鐘的飛行時間中 能夠前進最長的水平距離。 也使魷魚能輕易潛回水中 吸取更多水作為前進動力—— 或是迅速逃離鳥類掠食者。
But why do squids fly at all? Leading theories suggest that flight is an escape behaviour, as flying squid generally seem to be fleeing a nearby predator or ship. Other researchers think their flight may be an energy-saving migration strategy, because it takes less energy to move quickly through the air than through water. However, it’s also possible that learning to fly may be a vital part of surviving adolescence. Young, smaller squid can potentially fly faster and farther than their larger relatives. And since adult squid tend to cannibalize juveniles, soaring above the surf can help ensure these young squid will live to fly another day.
但到底為什麼魷魚要飛行? 主流理論認為飛行是一種逃跑行為, 因為飛行的魷魚通常看起來 像在逃離附近的掠食者或是船隻。 其他研究者認為魷魚的飛行行為 可能是迴游中節省能量的策略, 因為在空中快速移動所消耗的能量 比在水中低。 然而,學會飛行也有可能是 魷魚在成長期中存活的重要環節。 幼小的魷魚比其他體型較大的同族 能飛得更快、更遠。 而且因為成年魷魚有 掠食幼年體的傾向, 所以飛行於海面上將有助於幼小的魷魚 確保自己能夠再多活一天。